J2EE开源技术应用英文文献和中文翻译

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Application Specification of J2EE 1 Introduction This text analysis the mechanism of Hibernate and Struts, put forward 1 kind EE according to the J2 of the Hibernate and the Struts application development strategy.In this kind of strategy, the model layer use a Hibernate realization and see diagram and controller to then use a Struts frame a realization.So can consumedly lower the development efficiency that the Ou of code match sex and exaltation system. The key word Hibernate, Struts, the MVC, hold out for long time a layer one preface along with the Java technique of gradual mature and perfect, Be establishment business enterprise class application of standard terrace, the J2EE terrace got substantial of development.Several technique asked for help from to include in the J2 EE norm:Enterprise JavaBean(EJB), Java Servlets(Servlet), Java Server Pages(JSP), Java Message Service(JMS).etc., development many application system.But, also appeared some problem in the tradition J2 the EE the application of the development the process: the antinomy of of data model and logic model.Currently the database of usage basically and all is relation type database, but the Java be essentially a kind of the language which face to object, object at saving with read usage SQL and JDBC carry on a database operation and lowered plait distance of efficiency and system of can maintenance; tradition of J2 EE application much the adoption is according to the EJB heavy weight frame, this kind of frame suitable for develop a large business enterprise application, but usage the EJB container carry on development and adjust to try to need to be waste a great deal of time.For lowering the Out of code to match sex, exaltation system of development efficiency, this text put forward 1 kind EE according to the J2EE of the Struts frame and the Hibernate frame application development strategy.49288

2 Open Source Technology of J2EE

Datas' holding out for long time layer and Hibernate is one piece according to hold out for long time layer frame, is a kind of realization object and relation of the tool which reflect to shoot(O/R Mapping), it carried on the object of the lightweight to pack to the JDBC and make procedure member can usage object plait distance thought to operation database.It not only provided to shoot from Java to reflect of data form, but also provided a data a search and instauration mechanism.Opposite in usage JDBC and SQL to operation database, use a Hibernate ability consumedly of exaltation realization of efficiency.The Hibernate frame use allocation document of the form come to the reflect of the definition Java object and data form to shoot relation, in the meantime at more deep of level of data form of relation explanation for the relations such as inherit of and containment etc. of Java object.Pass the usage HQL language sentence complications of relation the calculate way use the way of object description, to a large extent simplification logarithms according to of search, speed development of efficiency.Have in the Hibernate a simple but keep the 论文网API of view, used for to the database mean of object performance search.Want to establish or the modification be these objects, need in the procedure carry on with them to hand over with each other, then tell Hibernate to keep.So, a great deal of pack hold out for long time turn operation of business logic no longer demand write a trivial JDBC language sentence, make data last long thus the layer got biggest of simplification.

Use the Struts realization MVC structure MVC(Model-View-Controller) is put forward by the Trygve Reenskaug, first drive application in the environment SmallTalk-80, is many to hand over with each other with interface system of constitute foundation.According to the need of variable of the interface design, MVC hand over with each other constitute of system to resolve into model and see diagram, controller three part. Model(Model) is software processing problem logic at independence in outside manifestation under contents and form circumstance of inside abstract, packed the core data, logic of problem and function of calculation relation, independence in concrete of interface expression and I/O operation.See diagram(View) mean information and particular form demonstration of model data and logic relation and appearance to the customer.It acquire a manifestation information from the model, there can be many for homology of information dissimilarity of manifestation form or see diagram.The controller(Controller) is a processing the customer hand over with software with each other operation of, its job is control provide model in any variety of dissemination, insure a customer interface among the model of rightness should contact;It accept a customer of importation, give° the importation feedback model, then realization compute model control, is make model and see diagram to moderate work of parts.Usually 1 see a diagram rightness should a controller.Model, see separate of diagram and controller, make a model be able to have many manifestation to see diagram.If the customer pass a certain see the controller of diagram change the data of model, all other dependence in these see of data diagram all should reflection arrive these variety.When therefore and regardless occurrence what data variety, controller all would variety notice allly see diagram, cause manifestation of renewal.This is actually a kind of variety of model-dissemination mechanism.